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dm thin: wake worker when discard is prepared
[linux-2.6.git] / net / caif / chnl_net.c
blobe597733affb82f088203bab569644f312e8d5463
1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Authors: Sjur Brendeland/sjur.brandeland@stericsson.com
4 * Daniel Martensson / Daniel.Martensson@stericsson.com
5 * License terms: GNU General Public License (GPL) version 2
6 */
7
8 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
9
10 #include <linux/fs.h>
11 #include <linux/hardirq.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/if_ether.h>
16 #include <linux/moduleparam.h>
17 #include <linux/ip.h>
18 #include <linux/sched.h>
19 #include <linux/sockios.h>
20 #include <linux/caif/if_caif.h>
21 #include <net/rtnetlink.h>
22 #include <net/caif/caif_layer.h>
23 #include <net/caif/cfpkt.h>
24 #include <net/caif/caif_dev.h>
25
26 /* GPRS PDP connection has MTU to 1500 */
27 #define GPRS_PDP_MTU 1500
28 /* 5 sec. connect timeout */
29 #define CONNECT_TIMEOUT (5 * HZ)
30 #define CAIF_NET_DEFAULT_QUEUE_LEN 500
31 #define UNDEF_CONNID 0xffffffff
32
33 /*This list is protected by the rtnl lock. */
34 static LIST_HEAD(chnl_net_list);
35
36 MODULE_LICENSE("GPL");
37 MODULE_ALIAS_RTNL_LINK("caif");
38
39 enum caif_states {
40 CAIF_CONNECTED = 1,
41 CAIF_CONNECTING,
42 CAIF_DISCONNECTED,
43 CAIF_SHUTDOWN
44 };
45
46 struct chnl_net {
47 struct cflayer chnl;
48 struct net_device_stats stats;
49 struct caif_connect_request conn_req;
50 struct list_head list_field;
51 struct net_device *netdev;
52 char name[256];
53 wait_queue_head_t netmgmt_wq;
54 /* Flow status to remember and control the transmission. */
55 bool flowenabled;
56 enum caif_states state;
57 };
58
59 static void robust_list_del(struct list_head *delete_node)
60 {
61 struct list_head *list_node;
62 struct list_head *n;
63 ASSERT_RTNL();
64 list_for_each_safe(list_node, n, &chnl_net_list) {
65 if (list_node == delete_node) {
66 list_del(list_node);
67 return;
68 }
69 }
70 WARN_ON(1);
71 }
72
73 static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
74 {
75 struct sk_buff *skb;
76 struct chnl_net *priv;
77 int pktlen;
78 const u8 *ip_version;
79 u8 buf;
80
81 priv = container_of(layr, struct chnl_net, chnl);
82 if (!priv)
83 return -EINVAL;
84
85 skb = (struct sk_buff *) cfpkt_tonative(pkt);
86
87 /* Get length of CAIF packet. */
88 pktlen = skb->len;
89
90 /* Pass some minimum information and
91 * send the packet to the net stack.
92 */
93 skb->dev = priv->netdev;
94
95 /* check the version of IP */
96 ip_version = skb_header_pointer(skb, 0, 1, &buf);
97 if (!ip_version) {
98 kfree_skb(skb);
99 return -EINVAL;
100 }
101
102 switch (*ip_version >> 4) {
103 case 4:
104 skb->protocol = htons(ETH_P_IP);
105 break;
106 case 6:
107 skb->protocol = htons(ETH_P_IPV6);
108 break;
109 default:
110 kfree_skb(skb);
111 priv->netdev->stats.rx_errors++;
112 return -EINVAL;
113 }
114
115 /* If we change the header in loop mode, the checksum is corrupted. */
116 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
117 skb->ip_summed = CHECKSUM_UNNECESSARY;
118 else
119 skb->ip_summed = CHECKSUM_NONE;
120
121 if (in_interrupt())
122 netif_rx(skb);
123 else
124 netif_rx_ni(skb);
125
126 /* Update statistics. */
127 priv->netdev->stats.rx_packets++;
128 priv->netdev->stats.rx_bytes += pktlen;
129
130 return 0;
131 }
132
133 static int delete_device(struct chnl_net *dev)
134 {
135 ASSERT_RTNL();
136 if (dev->netdev)
137 unregister_netdevice(dev->netdev);
138 return 0;
139 }
140
141 static void close_work(struct work_struct *work)
142 {
143 struct chnl_net *dev = NULL;
144 struct list_head *list_node;
145 struct list_head *_tmp;
146
147 rtnl_lock();
148 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
149 dev = list_entry(list_node, struct chnl_net, list_field);
150 if (dev->state == CAIF_SHUTDOWN)
151 dev_close(dev->netdev);
152 }
153 rtnl_unlock();
154 }
155 static DECLARE_WORK(close_worker, close_work);
156
157 static void chnl_hold(struct cflayer *lyr)
158 {
159 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
160 dev_hold(priv->netdev);
161 }
162
163 static void chnl_put(struct cflayer *lyr)
164 {
165 struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
166 dev_put(priv->netdev);
167 }
168
169 static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
170 int phyid)
171 {
172 struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
173 pr_debug("NET flowctrl func called flow: %s\n",
174 flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
175 flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
176 flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
177 flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
178 flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
179 flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
180 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");
181
182
183
184 switch (flow) {
185 case CAIF_CTRLCMD_FLOW_OFF_IND:
186 priv->flowenabled = false;
187 netif_stop_queue(priv->netdev);
188 break;
189 case CAIF_CTRLCMD_DEINIT_RSP:
190 priv->state = CAIF_DISCONNECTED;
191 break;
192 case CAIF_CTRLCMD_INIT_FAIL_RSP:
193 priv->state = CAIF_DISCONNECTED;
194 wake_up_interruptible(&priv->netmgmt_wq);
195 break;
196 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
197 priv->state = CAIF_SHUTDOWN;
198 netif_tx_disable(priv->netdev);
199 schedule_work(&close_worker);
200 break;
201 case CAIF_CTRLCMD_FLOW_ON_IND:
202 priv->flowenabled = true;
203 netif_wake_queue(priv->netdev);
204 break;
205 case CAIF_CTRLCMD_INIT_RSP:
206 caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
207 priv->state = CAIF_CONNECTED;
208 priv->flowenabled = true;
209 netif_wake_queue(priv->netdev);
210 wake_up_interruptible(&priv->netmgmt_wq);
211 break;
212 default:
213 break;
214 }
215 }
216
217 static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
218 {
219 struct chnl_net *priv;
220 struct cfpkt *pkt = NULL;
221 int len;
222 int result = -1;
223 /* Get our private data. */
224 priv = netdev_priv(dev);
225
226 if (skb->len > priv->netdev->mtu) {
227 pr_warn("Size of skb exceeded MTU\n");
228 kfree_skb(skb);
229 dev->stats.tx_errors++;
230 return NETDEV_TX_OK;
231 }
232
233 if (!priv->flowenabled) {
234 pr_debug("dropping packets flow off\n");
235 kfree_skb(skb);
236 dev->stats.tx_dropped++;
237 return NETDEV_TX_OK;
238 }
239
240 if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
241 swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
242
243 /* Store original SKB length. */
244 len = skb->len;
245
246 pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
247
248 /* Send the packet down the stack. */
249 result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
250 if (result) {
251 dev->stats.tx_dropped++;
252 return NETDEV_TX_OK;
253 }
254
255 /* Update statistics. */
256 dev->stats.tx_packets++;
257 dev->stats.tx_bytes += len;
258
259 return NETDEV_TX_OK;
260 }
261
262 static int chnl_net_open(struct net_device *dev)
263 {
264 struct chnl_net *priv = NULL;
265 int result = -1;
266 int llifindex, headroom, tailroom, mtu;
267 struct net_device *lldev;
268 ASSERT_RTNL();
269 priv = netdev_priv(dev);
270 if (!priv) {
271 pr_debug("chnl_net_open: no priv\n");
272 return -ENODEV;
273 }
274
275 if (priv->state != CAIF_CONNECTING) {
276 priv->state = CAIF_CONNECTING;
277 result = caif_connect_client(dev_net(dev), &priv->conn_req,
278 &priv->chnl, &llifindex,
279 &headroom, &tailroom);
280 if (result != 0) {
281 pr_debug("err: "
282 "Unable to register and open device,"
283 " Err:%d\n",
284 result);
285 goto error;
286 }
287
288 lldev = dev_get_by_index(dev_net(dev), llifindex);
289
290 if (lldev == NULL) {
291 pr_debug("no interface?\n");
292 result = -ENODEV;
293 goto error;
294 }
295
296 dev->needed_tailroom = tailroom + lldev->needed_tailroom;
297 dev->hard_header_len = headroom + lldev->hard_header_len +
298 lldev->needed_tailroom;
299
300 /*
301 * MTU, head-room etc is not know before we have a
302 * CAIF link layer device available. MTU calculation may
303 * override initial RTNL configuration.
304 * MTU is minimum of current mtu, link layer mtu pluss
305 * CAIF head and tail, and PDP GPRS contexts max MTU.
306 */
307 mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
308 mtu = min_t(int, GPRS_PDP_MTU, mtu);
309 dev_set_mtu(dev, mtu);
310 dev_put(lldev);
311
312 if (mtu < 100) {
313 pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
314 result = -ENODEV;
315 goto error;
316 }
317 }
318
319 rtnl_unlock(); /* Release RTNL lock during connect wait */
320
321 result = wait_event_interruptible_timeout(priv->netmgmt_wq,
322 priv->state != CAIF_CONNECTING,
323 CONNECT_TIMEOUT);
324
325 rtnl_lock();
326
327 if (result == -ERESTARTSYS) {
328 pr_debug("wait_event_interruptible woken by a signal\n");
329 result = -ERESTARTSYS;
330 goto error;
331 }
332
333 if (result == 0) {
334 pr_debug("connect timeout\n");
335 caif_disconnect_client(dev_net(dev), &priv->chnl);
336 priv->state = CAIF_DISCONNECTED;
337 pr_debug("state disconnected\n");
338 result = -ETIMEDOUT;
339 goto error;
340 }
341
342 if (priv->state != CAIF_CONNECTED) {
343 pr_debug("connect failed\n");
344 result = -ECONNREFUSED;
345 goto error;
346 }
347 pr_debug("CAIF Netdevice connected\n");
348 return 0;
349
350 error:
351 caif_disconnect_client(dev_net(dev), &priv->chnl);
352 priv->state = CAIF_DISCONNECTED;
353 pr_debug("state disconnected\n");
354 return result;
355
356 }
357
358 static int chnl_net_stop(struct net_device *dev)
359 {
360 struct chnl_net *priv;
361
362 ASSERT_RTNL();
363 priv = netdev_priv(dev);
364 priv->state = CAIF_DISCONNECTED;
365 caif_disconnect_client(dev_net(dev), &priv->chnl);
366 return 0;
367 }
368
369 static int chnl_net_init(struct net_device *dev)
370 {
371 struct chnl_net *priv;
372 ASSERT_RTNL();
373 priv = netdev_priv(dev);
374 strncpy(priv->name, dev->name, sizeof(priv->name));
375 return 0;
376 }
377
378 static void chnl_net_uninit(struct net_device *dev)
379 {
380 struct chnl_net *priv;
381 ASSERT_RTNL();
382 priv = netdev_priv(dev);
383 robust_list_del(&priv->list_field);
384 }
385
386 static const struct net_device_ops netdev_ops = {
387 .ndo_open = chnl_net_open,
388 .ndo_stop = chnl_net_stop,
389 .ndo_init = chnl_net_init,
390 .ndo_uninit = chnl_net_uninit,
391 .ndo_start_xmit = chnl_net_start_xmit,
392 };
393
394 static void chnl_net_destructor(struct net_device *dev)
395 {
396 struct chnl_net *priv = netdev_priv(dev);
397 caif_free_client(&priv->chnl);
398 free_netdev(dev);
399 }
400
401 static void ipcaif_net_setup(struct net_device *dev)
402 {
403 struct chnl_net *priv;
404 dev->netdev_ops = &netdev_ops;
405 dev->destructor = chnl_net_destructor;
406 dev->flags |= IFF_NOARP;
407 dev->flags |= IFF_POINTOPOINT;
408 dev->mtu = GPRS_PDP_MTU;
409 dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
410
411 priv = netdev_priv(dev);
412 priv->chnl.receive = chnl_recv_cb;
413 priv->chnl.ctrlcmd = chnl_flowctrl_cb;
414 priv->netdev = dev;
415 priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
416 priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
417 priv->conn_req.priority = CAIF_PRIO_LOW;
418 /* Insert illegal value */
419 priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
420 priv->flowenabled = false;
421
422 init_waitqueue_head(&priv->netmgmt_wq);
423 }
424
425
426 static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
427 {
428 struct chnl_net *priv;
429 u8 loop;
430 priv = netdev_priv(dev);
431 if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
432 priv->conn_req.sockaddr.u.dgm.connection_id) ||
433 nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
434 priv->conn_req.sockaddr.u.dgm.connection_id))
435 goto nla_put_failure;
436 loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
437 if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
438 goto nla_put_failure;
439 return 0;
440 nla_put_failure:
441 return -EMSGSIZE;
442
443 }
444
445 static void caif_netlink_parms(struct nlattr *data[],
446 struct caif_connect_request *conn_req)
447 {
448 if (!data) {
449 pr_warn("no params data found\n");
450 return;
451 }
452 if (data[IFLA_CAIF_IPV4_CONNID])
453 conn_req->sockaddr.u.dgm.connection_id =
454 nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
455 if (data[IFLA_CAIF_IPV6_CONNID])
456 conn_req->sockaddr.u.dgm.connection_id =
457 nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
458 if (data[IFLA_CAIF_LOOPBACK]) {
459 if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
460 conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
461 else
462 conn_req->protocol = CAIFPROTO_DATAGRAM;
463 }
464 }
465
466 static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
467 struct nlattr *tb[], struct nlattr *data[])
468 {
469 int ret;
470 struct chnl_net *caifdev;
471 ASSERT_RTNL();
472 caifdev = netdev_priv(dev);
473 caif_netlink_parms(data, &caifdev->conn_req);
474 dev_net_set(caifdev->netdev, src_net);
475
476 ret = register_netdevice(dev);
477 if (ret)
478 pr_warn("device rtml registration failed\n");
479 else
480 list_add(&caifdev->list_field, &chnl_net_list);
481
482 /* Use ifindex as connection id, and use loopback channel default. */
483 if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
484 caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
485 caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
486 }
487 return ret;
488 }
489
490 static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
491 struct nlattr *data[])
492 {
493 struct chnl_net *caifdev;
494 ASSERT_RTNL();
495 caifdev = netdev_priv(dev);
496 caif_netlink_parms(data, &caifdev->conn_req);
497 netdev_state_change(dev);
498 return 0;
499 }
500
501 static size_t ipcaif_get_size(const struct net_device *dev)
502 {
503 return
504 /* IFLA_CAIF_IPV4_CONNID */
505 nla_total_size(4) +
506 /* IFLA_CAIF_IPV6_CONNID */
507 nla_total_size(4) +
508 /* IFLA_CAIF_LOOPBACK */
509 nla_total_size(2) +
510 0;
511 }
512
513 static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
514 [IFLA_CAIF_IPV4_CONNID] = { .type = NLA_U32 },
515 [IFLA_CAIF_IPV6_CONNID] = { .type = NLA_U32 },
516 [IFLA_CAIF_LOOPBACK] = { .type = NLA_U8 }
517 };
518
519
520 static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
521 .kind = "caif",
522 .priv_size = sizeof(struct chnl_net),
523 .setup = ipcaif_net_setup,
524 .maxtype = IFLA_CAIF_MAX,
525 .policy = ipcaif_policy,
526 .newlink = ipcaif_newlink,
527 .changelink = ipcaif_changelink,
528 .get_size = ipcaif_get_size,
529 .fill_info = ipcaif_fill_info,
530
531 };
532
533 static int __init chnl_init_module(void)
534 {
535 return rtnl_link_register(&ipcaif_link_ops);
536 }
537
538 static void __exit chnl_exit_module(void)
539 {
540 struct chnl_net *dev = NULL;
541 struct list_head *list_node;
542 struct list_head *_tmp;
543 rtnl_link_unregister(&ipcaif_link_ops);
544 rtnl_lock();
545 list_for_each_safe(list_node, _tmp, &chnl_net_list) {
546 dev = list_entry(list_node, struct chnl_net, list_field);
547 list_del(list_node);
548 delete_device(dev);
549 }
550 rtnl_unlock();
551 }
552
553 module_init(chnl_init_module);
554 module_exit(chnl_exit_module);
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